This invention relates to multi-stage pumps and, more particularly, to multi-stage pumps wherein the stages thereof are embodied in an inner housing that is encapsulated in an outer housing.
It is a primary object of the present invention to afford a novel, multi-stage pump.
Another object of the present invention is to afford a novel multi-stage pump, which embodies an outer housing disposed around the stages thereof, in outwardly spaced relation thereto, to afford a chamber between the outer housing and the stages, which chamber forms a portion of the discharge or outlet passageway of the pump.
Another object of the present invention is to afford a novel, multi-stage pump of the aforementioned type, wherein, during operation of the pump, fluid is fed into the aforementioned chamber at a pressure effective to substantially equalize the pressures internally and radially outwardly of the stages of the pump.
Another object of the present invention is to afford a novel multi-stage pump of the aforementioned type, which is effective to pump liquids, such as, for example, liquified gases, at or near the boiling points thereof, as well as being effective to pump other liquids, such as, for example, water.
Multi-stage pumps for pumping liquids, at or near the boiling points thereof, have been heretofore known in the art, being shown, for example, in U.S. Pat. No. 2,875,968, issued to L. C. Roth, on Mar. 3, 1959, and the earlier U.S. Pat. No. 3,963,371, issued to L. J. Sieghartner, on June 15, 1976, and the copending application for U.S. Letters Patent, Ser. No. 935,604, filed in the U.S. Patent and Trademark Office on Aug. 21, 1978, by said L. J. Sieghartner, one of the above named co-inventors of the present invention. Such pumps have been highly successful. It is an important object of the present invention to afford improvements over the multi-stage pumps heretofore known in the art.
Yet another object of the present invention is to afford a multi-stage pump wherein liquid enters an inner housing and is discharged from an outer housing which is disposed around the inner housing in a novel and expeditious manner.
An object ancillary to the foregoing is to afford a novel multi-stage pump of the aforementioned type, wherein the liquid being discharged from the pump passes into the area between the inner and outer housing in such a manner as to surround at least a portion of the stages of the pump so as to tend, at least, to equalize the pressures in, and the external pressures radially surrounding the surrounded stages.
Another object of the present invention is to afford a novel multi-stage pump of the aforementioned type which is modular in construction, and which is constructed in such a manner that the various stages thereof may be readily assembled and separated, relative to each other.
A further object of the present invention is to afford a novel multi-stage pump of the aforementioned modular type wherein the internal and external pressures relative to the modules are balanced in a novel and expeditious manner effective to afford protection against leakage of liquid outwardly between the modules thereof.
Another object of the present invention is to afford a novel multi-stage pump, having the aforementioned modular construction, wherein modules thereof are encapsulated in a novel and expeditious manner.
Another object of the present invention is to afford a novel multi-stage pump of the aforementioned encapsulated, modular type, which may be either, solely, of a regenerative, turbine type or of a combination centrifugal-turbine type.
Yet another object of the present invention is to afford a novel multi-stage pump of the aforementioned encapsulated, modular type wherein, if desired, the pump may embody a liquid booster for feeding liquid upwardly from a liquid reservoir for discharge by the pump.
A further object of the present invention is to afford a novel multi-stage pump of the aforementioned encapsulated, modular type which is practical and efficient in operation, and which may be readily and economically produced commercially.
Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show the preferred embodiments of the present invention and the principles thereof and what we now consider to be the best mode in which we have contemplated applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.